The invention relates to a palletizing apparatus for palletizing stacks of loose materials such as newspapers, signatures, sheets of paper, rug tiles, flat bags, or open-flapped cases.
Apparatus for palletizing bundles of newspapers and apparatus for palletizing loose signature stacks are known in the art. However, the inventors know of no palletizer that is well suited for palletizing stacks of loose (unbound) newspapers.
One type of conventional palletizer for boxes or cartons uses a horizontally, reciprocally movable stripper plate for carrying boxes to a position above a pallet onto which the boxes are to be loaded. The stripper plate is then withdrawn from beneath the boxes, thereby depositing them onto the pallet. Retaining means are used for preventing the boxes from moving with the stripper plate as it is withdrawn. Such retaining means commonly include a bar which abuts the side of the boxes facing the direction of stripper plate withdrawal. This type of palletizer cannot be used for palletizing loose newspapers or the like.
A problem with palletizing stacks of loose newspapers or loose sheets of paper is that the sheet or sheets of paper immediately adjacent the stripper plate frequently stick to and move with the stripper plate as it is withdrawn.
Another problem with palletizing stacks of newspapers is that the upper surfaces of the stacks are usually uneven, rather than even. Also a stray flap will sometimes extend upwardly from the stack. Thus, it may be desirable to compress a previously deposited stack of papers before depositing an additional stack thereon. Also, an electric eye determining the level of a previously deposited stack of papers can be deceived by an upwardly extending flap, thereby causing the next stack of papers to be dropped from too great a distance above the previously deposited stack.
Attention is directed to the following U.S. patents which disclose palletizing apparatus:
Locke: U.S. Pat. No. 2,875,907 PA0 Woodcock: U.S. Pat. No. 2,875,908 PA0 Keys: U.S. Pat. No. 2,878,948 PA0 Gagnon: U.S. Pat. No. 3,149,732 PA0 Jeremiah: U.S. Pat. No. 3,166,203 PA0 Kampert: U.S. Pat. No. 3,257,006 PA0 Grasvoll: U.S. Pat. No. 3,594,977 PA0 Larson: U.S. Pat. No. 3,606,310 PA0 Brockmuller: U.S. Pat. No. 3,637,093 PA0 Grasvoll: U.S. Pat. No. 3,648,857 PA0 Carlson: U.S. Pat. No. 3,669,282 PA0 Alduk: U.S. Pat. No. 3,833,132 PA0 Golantsev: U.S. Pat. No. 3,837,140 PA0 Kelley: U.S. Pat. No. 4,030,618 PA0 Schmitt: U.S. Pat. No. 4,162,016 PA0 Schmitt: U.S. Pat. No. 4,195,959 PA0 Pantin: U.S. Pat. No. 4,205,934 PA0 Faltin: U.S. Pat. No. 4,230,311 PA0 Donnelly: U.S. Pat. No. 4,234,280 PA0 Meratti: U.S. Pat. No. 4,255,074 PA0 Cox: U.S. Pat. No. 4,342,531 PA0 Sylvander: U.S. Pat. No. 4,383,788 PA0 Werkheiser: U.S. Pat. No. 4,422,549 PA0 Werkheiser: U.S. Pat. No. 4,439,084 PA0 Wise: U.S. Pat. No. 4,477,067